大气等离子喷涂YSZ热障涂层内应力研究现状

Research Status of Atmospheric Plasma Spraying YSZ Thermal Barrier Coating Internal Stress

使用大气等离子喷涂(APS)技术制备氧化钇稳定氧化锆(YSZ)热障涂层(TBCs)已经得到广泛研究。内应力是影响TBCs系统性能和使用寿命的主要因素。过量的内应力会引起微裂纹的产生、扩展,导致YSZ TBCs过早失效。早期内应力主要由喷涂工艺、基体和粉末条件的不良选择引起,并引起早期裂纹的萌生与扩展。ZrO_(2)高温相变、热生长氧化物(TGO)生长和陶瓷与金属材料之间的热膨胀系数(CTE)失配是TBCs在热服役中内应力的主要来源。在内应力作用下,裂纹在表面陶瓷工作层(TC)/TGO或黏结层(BC)/TGO界面处萌生,扩张并导致涂层脱落失效。目前降低系统内应力以达到延长TBCs热服役寿命的主要思路有干预尖晶石TGO生成,制备复合涂层或使用稀土粒子稳定ZrO_(2)物相结构。

The preparation of yttrium-stabilized zirconia(YSZ)thermal barrier coatings(TBCs)using atmospheric plasma spraying(APS)has been extensively investigated.Internal stress is a major factor affecting the performance and service life of TBCs systems.Excessive internal stresses can cause the development and expansion of microcracks and lead to premature failure of YSZ TBCs.Early internal stresses are mainly caused by poor selection of the coating process,substrate and powder conditions,and cause early crack initiation and extension.High temperature phase changes in ZrO_(2),thermal growth oxide(TGO)growth and coefficient of thermal expansion(CTE)mismatch between ceramic and metallic materials are the main sources of internal stresses in TBCs in thermal service.Under internal stress,cracks sprout at the surface ceramic working layer(TC)/TGO or bonding layer(BC)/TGO interface,expand and lead to coating peeling failure.The main ideas to reduce the internal stresses in the system in order to extend the thermal service life of TBCs are to interfere with spinel TGO generation,to prepare composite coatings or to stabilise the ZrO_(2) phase structure with rare earth particles.